Traditional visual acuity tests are all performed by the subject indicating the orientation of the letters on the visual acuity test chart. The existing visual acuity test charts used are normally visual acuity charts printed. Moreover, it is also required that, the lighting of the environment for the visual acuity test is enough. Thus, for improving the lighting condition of the visual acuity test chart, the visual acuity test chart may be fixed on a surface of a light box to form a chart box, for visual acuity testing. Besides, the existing visual acuity tests all need a tester to point manually on the test chart or chart box.
If the pointing position is not explicit when the tester manually points on the test chart or chart box, the problem of the obtained test result being incorrect easily occurs; at the same time, since pointing manually is needed, it is troublesome to operate in effect and the labor cost is relatively large.